Method, device and battery management system for establishing battery allowable current model

Abstract

The present invention discloses a method and apparatus for establishing a battery allowable current model and a battery management system. The method for establishing the battery allowable current model includes: determining the open-circuit voltage U of the battery under a preset working condition OCV and the working cut-off voltage U cutoff ; according to the open-circuit voltage U OCV , the working cut-off voltage U cutoff and a plurality of preset working currents I with different magnitudes, calculating a plurality of critical internal resistances R, and each critical internal resistance R corresponds to each preset working current I one by one; according to the internal resistance change model of the battery under the preset working condition, the plurality of preset working currents I and the plurality of critical internal resistances R, determining a plurality of aging cycles, and each critical internal resistance R corresponds to each aging cycle one by one; according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, establishing the allowable current model of the battery. The method for establishing the battery allowable current model of the present invention solves the problem in the prior art that the allowable current of the battery in each aging cycle cannot be accurately predicted.

Description

Technical Field

[0001] The present invention relates to the field of battery management, and in particular, to a method, an apparatus, and a battery management system for establishing a battery allowable current model. Background Art

[0002] With the progress of technology, batteries play an irreplaceable role in more and more products. The maximum discharge power (allowable power) of a battery is different at different life stages. In actual use, it is crucial to obtain the maximum discharge power, which is of great significance for preventing over-discharge of the battery and increasing the battery service life.

[0003] For example, with the implementation of the specific policies of "carbon peak and carbon neutrality", new energy vehicles including battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), hybrid electric vehicles (HEV), and 48V systems have been vigorously promoted, further driving the rapid development of power lithium-ion batteries. The maximum discharge power of the battery system as the power source directly determines the output power of the electric vehicle to meet working conditions such as acceleration, overtaking, and climbing. Only by effectively controlling the maximum discharge power of the battery can the operating parameters of the electric vehicle be more reasonably determined and the battery life be guaranteed.

[0004] Under specific discharge conditions, the allowable power can be estimated based on the allowable current. Therefore, how to accurately obtain the allowable current of the battery at each stage of the life cycle has become an important issue. In the prior art, the allowable current of the battery at each aging cycle cannot be accurately predicted, resulting in poor battery health management.

[0005] To address the above problems, no effective solution has been proposed yet.

[0006] The above information disclosed in the background art section is only used to enhance the understanding of the background art of the technology described herein. Therefore, the background art may contain certain information that is not known to those skilled in the art as the existing prior art. Summary of the Invention

[0007] Embodiments of the present invention provide a method, an apparatus, and a battery management system for establishing a battery allowable current model, so as to at least solve the problem in the prior art that the allowable current of the battery at each aging cycle cannot be accurately predicted.

[0008] To achieve the above object, according to the first aspect of the embodiments of the present invention, a method for establishing a battery allowable current model is provided, including: determining the open-circuit voltage U of the battery under a preset working condition OCV and the working cut-off voltage U cut off ; according to the open-circuit voltage U OCV and the working cut-off voltage Ucut off and a plurality of preset working currents I with different magnitudes, calculate a plurality of critical internal resistances R, where each critical internal resistance R corresponds to each preset working current I one by one; according to the internal resistance change model of the battery under the preset working conditions, the plurality of preset working currents I, and the plurality of critical internal resistances R, determine a plurality of aging cycles, where each critical internal resistance R corresponds to each aging cycle one by one, and the internal resistance change model characterizes the relationship between the aging cycle, the preset working current I, and the critical internal resistance R under the preset working conditions; according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, establish a permissible current model of the battery, and the permissible current model characterizes the relationship between the aging cycle and the permissible current of the battery.

[0009] Further, the internal resistance change model includes a plurality of sub-models, where the plurality of sub-models correspond to the plurality of preset working currents I one by one, and each sub-model characterizes the relationship between the aging cycle and the critical internal resistance R.

[0010] Further, according to the open-circuit voltage U OCV 、the working cut-off voltage U cut off and a plurality of preset working currents I with different magnitudes, calculate a plurality of critical internal resistances R, including: according to the formula calculate each critical internal resistance R.

[0011] Further, before determining the plurality of aging cycles according to the internal resistance change model of the battery under the preset working conditions, the plurality of preset working currents I, and the plurality of critical internal resistances R, the method for establishing the battery permissible current model further includes: under the preset working conditions, for batteries with different aging cycles, use a plurality of test currents I XS for testing to obtain a plurality of test end voltages U XS ; according to the open-circuit voltage U OCV 、each test current I XS and the test end voltage U XS corresponding to the test current I XS , calculate a plurality of test end internal resistances R XS ; according to the plurality of aging cycles, the plurality of test currents I XS and the plurality of test end internal resistances R XS , establish an internal resistance change model.

[0012] Further, according to the open-circuit voltage U OCV 、each test current I XS and the test end voltage U XS corresponding to the test current I XS , calculate a plurality of test end internal resistances R XS , including: according to the formula calculate each test end internal resistance R XS .

[0013] Further, based on multiple aging cycles, multiple test currents I XS and multiple end-of-test internal resistances R XS , an internal resistance change model is established, including: for each test current I XS , respectively performing numerical fitting on the corresponding multiple aging cycles and the corresponding multiple end-of-test internal resistances R XS to obtain the internal resistance change model.

[0014] Further, for batteries with different multiple aging cycles, multiple test currents I with different magnitudes are all used XS for testing to obtain multiple end-of-test voltages U XS Before that, the method for establishing the allowable current model of the battery further includes: determining the initial allowable current I of the battery when it is in the initial state of its life and under a preset working condition max ; according to the initial allowable current I max , using a preset calculation rule to calculate multiple test currents I XS .

[0015] Further, determining the initial allowable current I of the battery when it is in the initial state of its life and under a preset working condition max , includes: under the preset working condition, using multiple preset currents with different magnitudes to separately test the battery in the initial state of its life; when testing the battery in the initial state of its life with a preset current ends, if the working voltage of the battery is the working cut-off voltage U cut off , then determining the corresponding preset current as the initial allowable current I max .

[0016] Further, the aging cycle characterizes at least one of the following: storage days, charge-discharge cycle times, energy throughput, capacity retention rate, gas production pressure, expansion pressure.

[0017] Further, the preset working condition includes at least one of the following conditions: preset working temperature, preset SOC, preset working duration, preset working current.

[0018] Further, the allowable current is the current when the battery discharges, or the allowable current is the current when the battery charges.

[0019] According to the second aspect of the embodiments of the present invention, a device for establishing an allowable current model of a battery is provided, including: a first determination unit for determining the open-circuit voltage U OCV and the working cut-off voltage U cut off of the battery under a preset working condition; a first calculation unit for according to the open-circuit voltage U OCV , the working cut-off voltage U cut offAnd a plurality of preset working currents I with different magnitudes are used to calculate a plurality of critical internal resistances R, and each critical internal resistance R corresponds to each preset working current I one by one; a second determination unit is configured to determine a plurality of aging cycles according to an internal resistance change model of the battery under a preset working condition, the plurality of preset working currents I, and the plurality of critical internal resistances R, and each critical internal resistance R corresponds to each aging cycle one by one, and the internal resistance change model represents the relationship between the aging cycle, the preset working current I, and the critical internal resistance R under the preset working condition; a first model establishment unit is configured to establish a permissible current model of the battery according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, and the permissible current model represents the relationship between the aging cycle and the permissible current of the battery.

[0020] According to the third aspect of the embodiments of the present invention, a non-volatile storage medium is provided. The non-volatile storage medium includes a stored program, wherein when the program runs, it controls the device where the non-volatile storage medium is located to execute the above-mentioned method for establishing a permissible current model of the battery.

[0021] According to the fourth aspect of the embodiments of the present invention, a processor is provided. The processor is used to run a program, wherein when the program runs, it executes the above-mentioned method for establishing a permissible current model of the battery.

[0022] According to the fifth aspect of the embodiments of the present invention, a battery management system is provided, including a battery, a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-mentioned method for establishing a permissible current model of the battery.

[0023] The method for establishing a permissible current model of the battery applying the technical solution of the present invention includes: determining the open-circuit voltage U of the battery under a preset working condition OCV and the working cut-off voltage U cut off ; according to the open-circuit voltage U OCV , the working cut-off voltage U cut off , and a plurality of preset working currents I with different magnitudes, calculating a plurality of critical internal resistances R, and each critical internal resistance R corresponds to each preset working current I one by one; according to the internal resistance change model of the battery under the preset working condition, the plurality of preset working currents I, and the plurality of critical internal resistances R, determining a plurality of aging cycles, and each critical internal resistance R corresponds to each aging cycle one by one, and the internal resistance change model represents the relationship between the aging cycle, the preset working current I, and the critical internal resistance R under the preset working condition; according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, establishing a permissible current model of the battery, and the permissible current model represents the relationship between the aging cycle and the permissible current of the battery. By determining the open-circuit voltage U OCV and the working cut-off voltage U cut off, by combining multiple preset working currents I of different magnitudes, multiple critical internal resistances R can be correspondingly calculated. That is, when the battery operates at each preset working current I until the cut-off state under the preset working conditions, at this time, each preset working current I is the allowable current of the battery under multiple different aging cycles under the corresponding preset working conditions. According to the internal resistance change model, the aging cycle corresponding to each preset working current I can be determined. Furthermore, an allowable current model of the battery can be established based on multiple preset currents I and the corresponding multiple aging cycles. Using the allowable current model of the battery, the allowable current of different aging cycles can be accurately and conveniently predicted, solving the problem in the prior art that the allowable current of the battery under each aging cycle cannot be accurately predicted. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0025] Figure 1 is a schematic flowchart of an optional embodiment of a method for establishing an allowable current model of a battery according to the present invention;

[0026] Figure 2 is a schematic diagram of an optional embodiment of an apparatus for establishing an allowable current model of a battery according to the present invention;

[0027] Figure 3 is a schematic diagram of an internal resistance change model of an optional embodiment of a method for establishing an allowable current model of a battery according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will refer to the drawings and combine the embodiments to detail this application.

[0029] In order to enable those skilled in the art of this technology to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0031] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element can be directly on the other element, or there may also be an intermediate element. Moreover, in the description and claims, when an element is described as being "connected" to another element, the element can be "directly connected" to the other element, or "connected" to the other element through a third element.

[0032] Figure 1 is a method for establishing a battery allowable current model according to an embodiment of the present invention, as Figure 1 shown, the method includes the following steps:

[0033] Step S102, determining the open-circuit voltage U of the battery under a preset working condition OCV and the working cut-off voltage U cut off ;

[0034] Step S104, according to the open-circuit voltage U OCV 、the working cut-off voltage U cut off and a plurality of preset working currents I with different magnitudes, calculating a plurality of critical internal resistances R, and each critical internal resistance R corresponds to each preset working current I one by one;

[0035] Step S106, according to the internal resistance change model of the battery under the preset working condition, a plurality of preset working currents I and a plurality of critical internal resistances R, determining a plurality of aging cycles, and each critical internal resistance R corresponds to each aging cycle one by one, and the internal resistance change model characterizes the relationship between the aging cycle, the preset working current I and the critical internal resistance R under the preset working condition;

[0036] Step S108, according to a plurality of preset working currents I and a plurality of aging cycles corresponding to the plurality of preset working currents I one by one, establishing an allowable current model of the battery, and the allowable current model characterizes the relationship between the aging cycle and the allowable current of the battery.

[0037] The method for establishing the allowable current model of a battery adopting the above solution includes: determining the open-circuit voltage U of the battery under a preset working condition OCV and the working cut-off voltage U cut off ; according to the open-circuit voltage U OCV , the working cut-off voltage U cut off and a plurality of preset working currents I with different magnitudes, calculating a plurality of critical internal resistances R, and each critical internal resistance R corresponds one-to-one to each preset working current I; according to the internal resistance change model of the battery under the preset working condition, the plurality of preset working currents I and the plurality of critical internal resistances R, determining a plurality of aging cycles, and each critical internal resistance R corresponds one-to-one to each aging cycle, and the internal resistance change model characterizes the relationship between the aging cycle, the preset working current I and the critical internal resistance R under the preset working condition; according to the plurality of preset working currents I and the plurality of aging cycles corresponding one-to-one to the plurality of preset working currents I, establishing the allowable current model of the battery, and the allowable current model characterizes the relationship between the aging cycle and the allowable current of the battery. By determining the open-circuit voltage U OCV and the working cut-off voltage U cut off of the battery under the preset working condition, combined with a plurality of preset working currents I with different magnitudes, a plurality of critical internal resistances R can be correspondingly calculated, that is, when the battery works at each preset working current I until the cut-off state under the preset working condition, at this time, each preset working current I is the allowable current of the battery under a plurality of different aging cycles under the corresponding preset working condition. And according to the internal resistance change model, the aging cycle corresponding to each preset working current I can be determined, and then the allowable current model of the battery can be established according to the plurality of preset currents I and the corresponding plurality of aging cycles. Using the allowable current model of the battery, the allowable current of different aging cycles can be accurately and conveniently predicted, solving the problem in the prior art that the allowable current of the battery under each aging cycle cannot be accurately predicted.

[0038] Specifically, the internal resistance change model includes a plurality of sub-models, and the plurality of sub-models correspond one-to-one to the plurality of preset working currents I, and each sub-model characterizes the relationship between the aging cycle and the critical internal resistance R.

[0039] That is to say, the internal resistance change model is divided into a plurality of sub-models according to different preset working currents I, and each sub-model characterizes the relationship between the aging cycle and the critical internal resistance R under the corresponding preset working current I.

[0040] As Figure 3 shown, in this embodiment, the internal resistance change model includes a plurality of functions, and each function corresponds one-to-one to each preset working current I1, I2, I3... I n , and each function characterizes the relationship between the internal resistance of the battery and the aging cycle under the corresponding preset working current I, where, in this embodiment, the aging cycle is specifically the storage time.

[0041] The specific form of the internal resistance change model can be diverse. For example, it can be a linear model, an exponential model, a linear-then-exponential model, or a combination thereof. In this embodiment, the internal resistance change model is in the form of a linear-then-exponential model, R = ax + b + m×e nx , where x represents the aging cycle, and a, b, m, and n are coefficients to be determined; whether the model is segmented and the determination of the segmentation inflection point need to be based on the specific battery type and the actual internal resistance growth. In a more specific embodiment, after x days of storage aging, with a pulsed current of 250 A and a pulse duration of 10 s, the internal resistance change model is R(x, 250 A, 10 s) = 0.0009x + 1.9639 + e -4.1705 ×e 0.0082x . The allowable current model also has a non-fixed specific form according to the actual situation.

[0042] According to the open-circuit voltage U OCV , the working cut-off voltage U cut off , and multiple preset working currents I of different magnitudes, multiple critical internal resistances R are calculated, including: calculating each critical internal resistance R according to the formula .

[0043] Specifically, before determining multiple aging cycles based on the internal resistance change model of the battery under preset working conditions, multiple preset working currents I, and multiple critical internal resistances R, the method for establishing the battery allowable current model further includes: under the preset working conditions, for batteries with different aging cycles, multiple test currents I XS are used for testing to obtain multiple test end voltages U XS ; according to the open-circuit voltage U OCV , each test current I XS , and the test end voltage U XS corresponding to the test current I XS , multiple test end internal resistances R XS are calculated; based on multiple aging cycles, multiple test currents I XS , and multiple test end internal resistances R XS , an internal resistance change model is established.

[0044] In this embodiment, the method for establishing the battery allowable current model further includes the step of establishing an internal resistance change model. By using multiple test currents I XS to test batteries with different aging cycles, and calculating the test end internal resistance R XS corresponding to each test current I XS according to the test results, and then multiple aging cycles, multiple of the said test currents I XS , and multiple test end internal resistances R XS, establish the internal resistance change model, which is convenient for subsequent use in the process of establishing the battery allowable current model.

[0045] According to the open-circuit voltage U OCV , each test current I XS and the test end voltage U XS corresponding to the test current I XS , calculate multiple test end internal resistances R XS , including: according to the formula calculate each test end internal resistance R XS .

[0046] Specifically, according to multiple aging cycles, multiple test currents I XS and multiple test end internal resistances R XS , establish the internal resistance change model, including: for each test current I XS , respectively perform numerical fitting on the corresponding multiple aging cycles and the corresponding multiple test end internal resistances R XS to obtain the internal resistance change model.

[0047] In this embodiment, for each test current I XS respectively adopt the method of numerical fitting to determine the relationship between multiple aging cycles and multiple test end internal resistances R XS , so that the internal resistance change model can clearly and accurately characterize the relationship between the aging cycle, the preset working current I and the critical internal resistance R under the preset working conditions.

[0048] Specifically, before testing multiple batteries with different aging cycles using multiple test currents I XS of different magnitudes to obtain multiple test end voltages U XS , the method for establishing the battery allowable current model further includes: determining the initial allowable current I max of the battery when it is in the initial state of life and under the preset working conditions; according to the initial allowable current I max , use the preset calculation rule to calculate multiple test currents I XS .

[0049] That is to say, each test current I XS is calculated according to the initial allowable current I max of the battery in the initial state of life using the preset calculation rule, that is, each test current I XS is associated with the initial allowable current I max , and based on the initial allowable current I max , it is more convenient to determine each test current I XS according to the battery aging law., which is beneficial to improving the reliability of sample collection and thus enhancing the accuracy of establishing the internal resistance change model.

[0050] Specifically, determine the initial allowable current I of the battery when it is in the initial state of life and under a preset working condition max , including: under the preset working condition, testing the battery in the initial state of life with multiple preset currents of different magnitudes respectively; when the test of the battery in the initial state of life with a preset current ends, if the working voltage of the battery is the working cut-off voltage U cut off , then determine the corresponding preset current as the initial allowable current I max .

[0051] In this embodiment, in the process of determining the initial allowable current I of the battery in the initial state of life max , the adopted method is: applying multiple preset currents of different magnitudes to test the battery in the initial state of life. If, when the test ends, the working voltage of the battery is exactly equal to the working cut-off voltage U cut off , then this preset current is the initial allowable current I corresponding to the battery in the initial state of life max . This method of using a trial current to determine the initial allowable current I max has the advantages of simple operation and high accuracy.

[0052] Specifically, the aging cycle characterizes at least one of the following: storage days, charge-discharge cycle times, energy throughput, capacity retention rate, gas production pressure, expansion pressure. The battery aging path may include: calendar aging, cycle aging, working condition cycle, cycle-storage interaction (including cycling first and then storing, storing first and then cycling, storing for a certain time and then cycling to the EOL state, and cycling a certain number of turns or energy throughput and then storing to the EOL state). The aging conditions include: temperature (-30°C to 100°C), SOC (0 - 100%), DOD (depth of discharge, 0 - 100%), and rate (0.1C - 100C).

[0053] The preset working condition includes at least one of the following conditions: preset working temperature, preset SOC, preset working duration, preset working current.

[0054] In specific implementation, the allowable current can be the current when the battery discharges, or the allowable current can also be the current when the battery charges.

[0055] Secondly, as Figure 2 shown, an embodiment of the present invention also provides a device for establishing a battery allowable current model, including: a first determination unit for determining the open-circuit voltage U of the battery under a preset working condition OCV and the working cut-off voltage U cut off; The first calculation unit is configured to calculate a plurality of critical internal resistances R according to the open-circuit voltage U OCV , the working cut-off voltage U cut off , and a plurality of preset working currents I with different magnitudes, where each critical internal resistance R corresponds to each preset working current I one by one; the second determination unit is configured to determine a plurality of aging cycles according to the internal resistance change model of the battery under a preset working condition, the plurality of preset working currents I, and the plurality of critical internal resistances R, where each critical internal resistance R corresponds to each aging cycle one by one, and the internal resistance change model characterizes the relationship between the aging cycle, the preset working current I, and the critical internal resistance R under the preset working condition; the first model establishment unit is configured to establish a permissible current model of the battery according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, and the permissible current model characterizes the relationship between the aging cycle and the permissible current of the battery.

[0056] Specifically, the internal resistance change model includes a plurality of sub-models, the plurality of sub-models correspond to the plurality of preset working currents I one by one, and each sub-model characterizes the relationship between the aging cycle and the critical internal resistance R.

[0057] The first calculation unit is configured to: calculate each critical internal resistance R according to the formula .

[0058] Specifically, the apparatus for establishing the battery permissible current model further includes an acquisition unit, a second calculation unit, and a second model establishment unit: the acquisition unit is configured to, before determining the plurality of aging cycles according to the internal resistance change model of the battery under the preset working condition, the plurality of preset working currents I, and the plurality of critical internal resistances R, under the preset working condition, for a plurality of batteries with different aging cycles, use a plurality of test currents I with different magnitudes XS to perform tests and obtain a plurality of test end voltages U XS ; the second calculation unit is configured to calculate a plurality of test end internal resistances R according to the open-circuit voltage U OCV , each test current I XS , and the test end voltage U XS corresponding to the test current I XS ; the second model establishment unit is configured to establish an internal resistance change model according to the plurality of aging cycles, the plurality of test currents I XS , and the plurality of test end internal resistances R XS . XS

[0059] The second calculation unit is configured to: calculate each test end internal resistance R according to the formula . XS

[0060] Specifically, the second model establishment unit is configured to: for each test current I XS, respectively perform numerical fitting on the corresponding multiple aging cycles and the corresponding multiple end-of-test internal resistances R XS to obtain an internal resistance change model.

[0061] The device for establishing the allowable current model of the battery further includes a third determination unit and a third calculation unit: the third determination unit is configured to, for batteries with different aging cycles, adopt multiple test currents I with different magnitudes XS for testing, and obtain multiple end-of-test voltages U XS before determining the initial allowable current I of the battery when it is in the initial state of its life and under a preset working condition max ; the third calculation unit is configured to calculate multiple test currents I according to the initial allowable current I max using a preset calculation rule. XS .

[0062] Specifically, the third determination unit includes a test module and a determination module: the test module is configured to, under a preset working condition, respectively test the battery in the initial state of its life using multiple preset currents with different magnitudes; the determination module is configured to, when the test of the battery in the initial state of its life using a preset current ends, if the working voltage of the battery is the working cut-off voltage U cut off , then determine the corresponding preset current as the initial allowable current I max .

[0063] The aging cycle characterizes at least one of the following: storage days, charge-discharge cycle times, energy throughput, capacity retention rate, gas production pressure, expansion pressure.

[0064] The preset working condition includes at least one of the following conditions: preset working temperature, preset SOC, preset working duration, preset working current.

[0065] In specific implementation, the allowable current can be the current when the battery discharges, or the allowable current can also be the current when the battery charges.

[0066] In addition, an embodiment of the present invention further provides a non-volatile storage medium, the non-volatile storage medium includes a stored program, wherein when the program runs, it controls the device where the non-volatile storage medium is located to execute the above-mentioned method for establishing the allowable current model of the battery.

[0067] Furthermore, an embodiment of the present invention further provides a processor, the processor is used to run a program, wherein when the program runs, it executes the above-mentioned method for establishing the allowable current model of the battery.

[0068] Finally, an embodiment of the present invention also provides a battery management system, including a battery, a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for establishing the battery allowable current model described above is implemented.

[0069] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments. Moreover, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0070] In the above embodiments of the present invention, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] In several embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units can be a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces. The indirect couplings or communication connections of the units or modules can be in an electrical or other form.

[0072] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0073] In addition, the functional units in each embodiment of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0074] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media that can store program codes, such as USB flash drives, read-only memories (ROMs), random access memories (RAMs), mobile hard disks, magnetic disks, or optical discs.

[0075] The foregoing are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for establishing a battery allowable current model, characterized in that, Comprising: Determine the open-circuit voltage U of the battery under preset working conditions OCV and the working cut-off voltage U cutoff ; According to the open-circuit voltage U OCV , the operating cut-off voltage U cutoff and a plurality of preset operating currents I with different magnitudes, calculate a plurality of critical internal resistances R, and each of the critical internal resistances R corresponds to each of the preset operating currents I one by one; Determining a plurality of aging cycles according to the internal resistance change model of the battery under the preset working conditions, a plurality of the preset working currents I, and a plurality of the critical internal resistances R, where each of the critical internal resistances R corresponds to one of the aging cycles, the internal resistance change model characterizes the relationship between the aging cycle, the preset working current I, and the critical internal resistance R under the preset working conditions, the internal resistance change model includes a plurality of sub-models, the plurality of sub-models correspond to the plurality of preset working currents I one by one, and each of the sub-models characterizes the relationship between the aging cycle and the critical internal resistance R; Establishing a permissible current model of the battery according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, where the permissible current model characterizes the relationship between the aging cycle and the permissible current of the battery; Before determining a plurality of aging cycles according to the internal resistance change model of the battery under the preset working conditions, a plurality of the preset working currents I, and a plurality of the critical internal resistances R, the method for establishing the allowable current model of the battery further includes: under the preset working conditions, for the batteries with different aging cycles, a plurality of test currents I with different magnitudes are all adopted XS to perform tests to obtain a plurality of end-of-test voltages U XS ; according to the open-circuit voltage U OCV , each of the test currents I XS , and the end-of-test voltage U XS corresponding to the test current I XS , calculate a plurality of end-of-test internal resistances R XS ; according to the plurality of aging cycles, the plurality of test currents I XS , and the plurality of end-of-test internal resistances R XS , establish the internal resistance change model.

2. The method for establishing the allowable current model of the battery according to claim 1, characterized in that Based on the multiple aging cycles and the multiple test currents I XS and the multiple end-of-test internal resistances R XS , establish the internal resistance change model, including: For each of the test currents I XS , numerical fitting is respectively performed on the corresponding multiple aging cycles and the corresponding multiple end-of-test internal resistances R XS to obtain the internal resistance change model.

3. The method for establishing a battery allowable current model according to claim 1, characterized in that, For the batteries with different numbers of aging cycles, a plurality of test currents I with different magnitudes are used XS to perform tests and obtain a plurality of end-of-test voltages U XS Before that, the method for establishing the allowable current model of the battery further includes: Determine the initial allowable current I of the battery in the initial state of its life and under the preset operating conditions max ; According to the initial allowable current I max , a plurality of the test currents I are calculated by using a pre-designed calculation rule XS .

4. The method for establishing the allowable current model of the battery according to claim 3, characterized in that, Determine the initial allowable current I of the battery when it is in the initial state of its life and under the preset operating conditions max , including: Under the preset working conditions, respectively testing the battery in the initial state of its life with a plurality of preset currents of different magnitudes; At the end of testing the battery in the initial state of life with one of the preset currents, if the working voltage of the battery is the working cut-off voltage U cutoff , then determine the corresponding preset current as the initial allowable current I max .

5. The method for establishing a battery allowable current model according to any one of claims 1 to 4, characterized in that, The preset working conditions include at least one of the following conditions: Preset working temperature, preset SOC, preset working duration, preset working current.

6. The method for establishing a battery allowable current model according to any one of claims 1 to 4, characterized in that The permissible current is the current when the battery discharges, or the permissible current is the current when the battery charges.

7. An apparatus for establishing a battery allowable current model, characterized in that, Comprising: A first determination unit, configured to determine an open-circuit voltage U of a battery under a preset working condition OCV and a working cut-off voltage U cutoff ; The first calculation unit is configured to calculate a plurality of critical internal resistances R according to the open-circuit voltage U OCV , the operating cut-off voltage U cutoff and a plurality of preset operating currents I with different magnitudes, and each of the critical internal resistances R corresponds to each of the preset operating currents I one by one; A second determination unit, configured to determine a plurality of aging cycles according to the internal resistance change model of the battery under the preset working conditions, a plurality of the preset working currents I, and a plurality of the critical internal resistances R, where each of the critical internal resistances R corresponds to one of the aging cycles, the internal resistance change model characterizes the relationship between the aging cycle, the preset working current I, and the critical internal resistance R under the preset working conditions, the internal resistance change model includes a plurality of sub-models, the plurality of sub-models correspond to the plurality of preset working currents I one by one, and each of the sub-models characterizes the relationship between the aging cycle and the critical internal resistance R; A first model establishment unit, configured to establish a permissible current model of the battery according to the plurality of preset working currents I and the plurality of aging cycles corresponding to the plurality of preset working currents I one by one, where the permissible current model characterizes the relationship between the aging cycle and the permissible current of the battery; The device further includes: an acquisition unit configured to, under the preset working conditions, for the plurality of batteries with different aging cycles, adopt a plurality of test currents I with different magnitudes XS to perform tests and acquire a plurality of end-of-test voltages U XS ; A second calculation unit, configured to calculate a plurality of end-of-test internal resistances R according to the open-circuit voltage U OCV , each of the test currents I XS , and the end-of-test voltage U corresponding to the test current I XS ; and a second model establishment unit, configured to establish the internal resistance change model according to a plurality of the aging cycles, a plurality of the test currents I XS , and a plurality of the end-of-test internal resistances R XS ; XS ; and a second model establishment unit, configured to establish the internal resistance change model according to a plurality of the aging cycles, a plurality of the test currents I XS .

8. A battery management system, comprising a battery, a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the method for establishing the battery permissible current model according to any one of claims 1 to 6 is implemented.

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